A Method and Apparatus for Controlling a Hazardous Device

ABSTRACT

A method of controlling a hazardous device comprising the steps of providing a combination of a barrage unit and a container for holding a liquid, the container being adapted to receive the barrage unit, the barrage unit comprising at least one pad, the pad comprising an absorbent fibrous material and an absorbent crystalline material; arranging the hazardous device and barrage unit in the container with the barrage unit at least partially covering the hazardous device; and, adding a liquid to the container so that the barrage unit absorbs the liquid.

The present invention relates to a method and apparatus for controllinga hazardous device. More particularly, but not exclusively, the presentinvention relates to an apparatus for controlling a hazardous devicecomprising a barrage unit comprising a pad sandwiched between first andsecond liner layers, the pad comprising an absorbent fibrous materialand absorbent crystalline material; and, a container for holding aliquid, the container being dimensioned to receive the barrage unit. Ina further aspect the present invention relates to a method ofcontrolling a hazardous device. More particularly, but not exclusivelythe method according to the invention comprises the steps of providingthe above apparatus, arranging the hazardous device and barrage unit inthe container and then adding a liquid to the container such that it isabsorbed by the barrage unit.

Hazardous devices in vehicles, in particular aircraft, are becoming anincreasing problem. Of particular concern are batteries for mobilephones, laptops and the like. Such batteries can become hot and so riskcausing a fire. In extreme cases they can explode. Despite thiseffective measures of containing such hazardous devices are often notavailable to the crew. This is particularly the case on aircraft. Whilstblast or fire containing blankets are known they tend to be heavy andbulky. On aircraft both weight and space are at a premium and because ofthis such blankets are typically not carried on aircraft.

The present invention seeks to overcome the problems of the prior art.

Accordingly, in a first aspect the present invention provides a methodof controlling a hazardous device comprising the steps of

-   -   providing a combination of a barrage unit and a container for        holding a liquid, the container being adapted to receive the        barrage unit, the barrage unit comprising at least one pad, the        pad comprising an absorbent fibrous material and an absorbent        crystalline material;    -   arranging the hazardous device and barrage unit in the container        with the barrage unit at least partially covering the hazardous        device; and,    -   adding a liquid to the container so that the barrage unit        absorbs the liquid.

The barrage unit is stored on the aircraft in a dry state and so islight and takes up little space. If a hazardous device is identified thedevice and barrage unit are placed in the container and the barrage unitrapidly hydrated by the addition of a liquid. The barrage unit willtypically absorb several hundred times its weight in liquid. The barrageunit will cool the hazardous device. It will also contain the blast ifthe device should explode. The barrage unit can be hydrated usingliquids which are already carried on an aircraft such as water and softdrinks.

Preferably the pad is sandwiched between first and second liner layers.

The liquid can be added to the container before at least one of thehazardous device and barrage unit.

Preferably the container is a tray.

Preferably, the tray is a sealed container with the barrage unitpre-packed in the tray.

Preferably, the container is a bag.

The barrage unit can be shaped as a blanket.

Alternatively, the barrage unit can be shaped as a pouch for receivingthe hazardous device.

Preferably the pouch comprises first and second side walls, each sidewall comprising a pad.

Preferably, the absorbent crystalline material is a polymeric material

Preferably, the polymeric material is a superabsorbent polymer.

Preferably, the superabsorbent polymer is one or more polyacrylate orpolyamide, preferably one of more polyacrylate or polyamide salts.

Preferably, the salt is one or more metal salt, preferably a sodium orpotassium salt.

Preferably, the fibrous material is a cellulosic material, preferablypulp fibre.

Preferably, the liner layers are a hydrophilic material, preferablycotton.

In a further aspect of the invention there is provided an apparatus forcontrolling a hazardous device comprising

-   -   a barrage unit comprising at least one pad sandwiched between        first and second liner layers, the pad comprising an absorbent        fibrous material and an absorbent crystalline material; and,    -   a container for holding a liquid, the container being        dimensioned to receive the barrage unit.

The container can be a tray.

The container can be a bag.

The barrage unit can be shaped as a blanket.

The barrage unit can be shaped as a pouch.

The present invention will now be described by way of example only onnot in any limitative sense with reference to the accompanying drawingsin which

FIG. 1 shows a barrage unit of an apparatus according to the invention;

FIG. 2 shows a second embodiment of a barrage unit of an apparatusaccording to the invention;

FIG. 3(a) shows an apparatus according to the invention with the barrageunit in the dry state;

FIG. 3(b) shows an apparatus of FIG. 3(a) with the barrage unit in thewet state;

FIG. 4(a) shows a further embodiment of an apparatus according to theinvention; and,

FIG. 4(b) shows the apparatus of FIG. 4(a) in the wet state.

Shown in FIG. 1 is a barrage unit 1 of an apparatus according to theinvention. The barrage unit 1 comprises a pad 2 sandwiched between firstand second liner layers 3,4. The pad 2 comprises a mixture of anabsorbent fibrous material and an absorbent crystalline material.

The pad 2 is typically rectangular although other shapes of pad such assquare, round or oval are possible.

The absorbent crystalline material is preferably a polymeric materialsuch as a superabsorbent polymer. A number of different superabsorbentpolymers are available for example polyacrylates and or polyacrylamides,especially polyacrylate and/or polyacrylamide salts, such as alkalimetal salts eg sodium or potassium metal salts. These types of substancecan hold up to two hundred times their own weight of water as thecrystals can form an absorbent gelling polymer when saturated withfluid. It is well understood by one skilled in the art that mixtures ofsuperabsorbent polymers may be used.

Other materials are also used to make a superabsorbent polymer, such asa polyacrylamide copolymer, ethefene maleic anhydride copolymer, crosslinked carboxy-methyl-cellulose, polyvinyl alcohol copolymers, crosslinked polyethylene oxide and starch grafted copolymer ofpolyacrylonitrile.

The fibrous material preferably comprises a cellulosic material, forexample a pulp fibre, such as a wood pulp or fibre crop material such asa cotton pulp or the like. There are numerous other fibre crop materialsavailable and it will be appreciated by the person skilled in the artthat a number of such materials and/or mixtures of such materials may beused, Preferably the fibrous material is biodegradable.

The ratio of absorbent crystalline material to absorbent fibrousmaterial may vary and may depend on a number of factors such as thenature of the crystalline material eg the superabsorbent polymer and thenature of the fibrous material eg pulp material. Thus for example thefibrous material may comprise from 40% to 80% by weight, preferably from50% to 70% by weight, more preferably 55% to 65% by weight, thecrystalline material making all or a substantial portion of theremainder of the pad.

The liner layers 3,4 typically comprise a hydrophilic material such ascotton or fibrework. The upper and lower liner layers 3,4 are cut duringmanufacture around the pads 2 and then the edges 5 typically gluedtogether. The layers 3,4 may be sealed together in other ways.

The pad 2 can be manufactured in a number of different ways. Oneapproach is to simply mix the absorbent fibrous material and absorbentcrystalline material together, either mechanically or by hand. A furtherapproach is to lay the fibrous material and crystalline material down inalternating layers. A more preferred approach however is to flow thefibrous material into a rotating drum then then drop the crystallinematerial into the drum. Once thoroughly mixed the fibrous material andcrystalline material are extruded from an aperture in the side wall ofthe drum onto a liner layer 3 in the form of a pad 2. A second linerlayer 4 is then laid down on the first sealing the pad 2 therebetween.Manufacturing the pad 2 in this way distributes the crystalline materialmore evenly throughout the fibrous material. Pads 2 manufactured by thismethod tend to expand more quickly and evenly than pads manufactured byother methods.

Shown in FIG. 2 is a further example of a barrage unit 1 according tothe invention. This barrage unit 1 comprises a plurality of pads 2 in asack 6. The sack 6 is any conventional material known as sackingmaterial. It may be a natural material or a synthetic material or acombination of such materials. An example of a natural material is ajute fabric. An example of a synthetic material is a loosely wovenpolypropelene. A jute fabric is preferred because of, inter alia, itshyrophilicity. The sack 6 may be biodegradeable.

Shown in FIG. 3(a) is an apparatus 7 according to the invention. Theapparatus 7 comprises a barrage unit 1 as described above and shaped asa blanket in combination with a container 8 for holding a liquid whichin this embodiment is a tray 8. The barrage unit 1 is in the dry state.The tray 8 is dimensioned to receive the barrage unit 2. Typically thetray 8 is sealed by a water impermeable film 9 stretched across themouth of the tray 8 as shown. The tray 8 may also comprise a sachet 10of a water absorbing material to keep the barrage unit 2 dry.

In use the barrage unit 1 and tray 8 are loaded on to a vehicle, forexample an aircraft where it is stored until needed. In the dry statethe barrage unit 1 is relatively thin and light and does not take upmuch volume.

When a potentially hazardous device 11 (for example a lithium, batteryfor a mobile device) is identified the film 9 is removed from the tray.The hazardous device 11 is placed in the tray 8 and covered, at leastpartially, with the barrage unit 1. Liquid 12 is poured into the tray 8.The liquid can be any liquid commonly carried by the aircraft, forexample drinking water, soft drinks, wines etc. The barrage unit 1rapidly absorbs the liquid 12 and swells as shown in FIG. 3(b). It maybe necessary to add the liquid 12 to the tray several times before thebarrage unit 1 reaches its full volume.

The barrage unit 1 cools the hazardous device 11 and will also containany flames if it should ignite. It also contains any blast fragmentationpieces if the hazardous device 11 should explode.

The barrage unit 1 may not be stored in the tray 8. One or more barrageunits 1 may be stored separately from the tray 8 if preferred.

The barrage unit 1 has other secondary uses. When in the dry state thebarrage unit 1 can be used to mop up spillages of liquids or toiletoverflow. ft can also be used to plug leaks.

The apparatus 7 can be used in any vehicle but particularly those whereweight and space are at a premium. Other examples are trains and boats.

Shown in FIG. 4(a) is a further embodiment of an apparatus according tothe invention. In this embodiment the container 8 is a bag 8 having acloseable flap 13. The bag 8 is typically a plastics materialimpermeable to liquids. The apparatus further comprises a barrage unit1. The barrage unit 1 is shaped as a pouch dimensioned to receive thehazardous device. Each side wall 14, 15 of the pouch 1 comprises atleast one pad 16, 17 sandwiched between liner layers 2,3. The barrageunit 1 has a closeable flap 18.

FIG. 4(b) shows the apparatus of FIG. 4(a) in use. When a hazardousdevice 11 is identified it is placed in the pouch 1 and the flap 18closed. The barrage unit 1 is then placed in the bag 8. The bag 8 isfilled with a liquid 12 and the flap 13 closed. The pads 16,17 expand byabsorbing the liquid 12 as shown. In this state the apparatus cools thehazardous device 11 and again contains any blast fragments.

In the above described embodiments the liquid is added as a last step.In alternative embodiments according to the invention the liquid isadded to the container at different points in the method. As an examplewhere the barrage unit is a pouch and the container is a bag the liquidmay be added to the bag, the device added to the pouch and the pouchplaced in the bag. Alternatively, the liquid and the pouch may be addedto the bag and then finally the device added to the pouch in the bag.

A typical hazardous device is a battery such as a lithium battery.Batteries can overheat and possibly explode. The liquid employed in thedevice will cool the battery and prevent it from igniting. If thebattery does explode the apparatus will control the blast. There areother types of hazardous device which may occasionally be found on anaircraft. These include munitions such as bombs or bullets. Again, theliquid may prevent the munitions from exploding. If the munitions doexplode the apparatus will contain the blast.

1. A method of controlling a hazardous device comprising the steps ofproviding a combination of a barrage unit and a container for holding aliquid, the container being adapted to receive the barrage unit, thebarrage unit comprising at least one pad, the pad comprising anabsorbent fibrous material and an absorbent crystalline material;arranging the hazardous device and barrage unit in the container withthe barrage unit at least partially covering the hazardous device; andadding a liquid to the container so that the barrage unit absorbs theliquid.
 2. A method as claimed in claim 1, wherein the pad is sandwichedbetween first and second liner layers.
 3. A method as claimed in claim1, wherein the liquid is added to the container before the step ofarranging the hazardous device and barrage unit in the container.
 4. Amethod as claimed in claim 1, wherein the container is a tray.
 5. Amethod as claimed in claim 4, wherein the tray is a sealed containerwith the barrage unit pre-packed in the tray.
 6. A method as claimed inclaim 1, wherein the container is a bag.
 7. A method as claimed in claim1, wherein the barrage unit is shaped as a blanket.
 8. A method asclaimed in claim 1, wherein the barrage unit is shaped as a pouch forreceiving the hazardous device.
 9. A method as claimed in claim 8,wherein the pouch comprises first and second side walls, each side wallcomprising the pad.
 10. A method as claimed in claim 1, wherein theabsorbent crystalline material is a polymeric material.
 11. A method asclaimed in claim 10, wherein the polymeric material is a superabsorbentpolymer.
 12. A method as claimed in claim 11, wherein the superabsorbentpolymer is one or more polyacrylate or polyamide.
 13. A method asclaimed in claim 2, wherein the one or more polyacrylate salt orpolyamide salt is one or more metal salt.
 14. A method as claimed inclaim 1, wherein the fibrous material is a cellulosic material.
 15. Amethod as claimed in claim 2, wherein each of the liner layers comprisesa hydrophilic material.
 16. An apparatus for controlling a hazardousdevice comprising a barrage unit comprising at least one pad, the padcomprising an absorbent fibrous material and an absorbent crystallinematerial; and a container for holding a liquid, the container beingdimensioned to receive the barrage unit.
 17. An apparatus as claimed inclaim 16, wherein the container is a tray.
 18. An apparatus as claimedin claim 16, wherein the container is a bag.
 19. An apparatus as claimedin claim 16, wherein the barrage unit is shaped as a blanket.
 20. Anapparatus as claimed in claim 16, wherein the barrage unit is shaped asa pouch.
 21. A method as claimed in claim 12, wherein the one or morepolyacrylate salt or polyamide salt.
 22. A method as claimed in claim13, wherein the one or more metal salt is a sodium metal salt or apotassium metal salt.
 23. A method as claimed in claim 14, wherein thecellulosic material is pulp fibre.
 24. A method as claimed in claim 15,wherein the hydrophilic material is cotton.